Enhancement: Add metadata extraction and updation support

[abhiTronix]

Detailed Description

This issue will implement source metadata extraction and updation support through python's builtin @property decorator which makes usage of getter and setters much easier in Object-Oriented Programming.

Roadmap

• [x] Add metadata property object function to FFdecoder API
  • The property object will retrieve source metadata form Sourcer API as dict and convert it into JSON dump for pretty printing.
• [x] Add metadata property object with setter() method for updating source metadata with user-defined dictionary.
• [x] Add retrieve_metadata class method to Sourcer API.
  • The retrieve_metadata will returns Source metadata as python dictionary.
• [x] Move FFmpeg path validation and handling to Sourcer API.

Context

This issue will oversee implementation source metadata extraction and updation support through python @property decorator.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to change)